Structural and Functional Characterization of Camelus dromedarius Glutathione Transferase M1-1.

Fereniki Perperopoulou,Nirmal Poudel,Anastassios C Papageorgiou,Nikolaos E Labrou,Farid S Ataya

doi:10.3390/life12010106

Abstract

Glutathione transferases (GSTs; EC. 2.5.1.18) are a large family of multifunctional enzymes that play crucial roles in the metabolism and inactivation of a broad range of xenobiotic compounds. In the present work, we report the kinetic and structural characterization of the isoenzyme GSTM1-1 from Camelus dromedarius (CdGSTM1-1). The CdGSΤM1-1 was expressed in E. coli BL21 (DE3) and was purified by affinity chromatography. Kinetics analysis showed that the enzyme displays a relative narrow substrate specificity and restricted ability to bind xenobiotic compounds. The crystal structures of CdGSΤM1-1 were determined by X-ray crystallography in complex with the substrate (GSH) or the reaction product (S-p-nitrobenzyl-GSH), providing snapshots of the induced-fit catalytic mechanism. The thermodynamic stability of CdGSTM1-1 was investigated using differential scanning fluorimetry (DSF) in the absence and in presence of GSH and S-p-nitrobenzyl-GSH and revealed that the enzyme’s structure is significantly stabilized by its ligands. The results of the present study advance the understanding of camelid GST detoxification mechanisms and their contribution to abiotic stress adaptation in harsh desert conditions.

Highlights

IntroductionMammals are exposed to many factors that can affect their functions or even cause their demise
Published: 12 January 2022Mammals are exposed to many factors that can affect their functions or even cause their demise
Recombinant CdGSTM1-1 was purified in a single-step by affinity chromatography using a GSH-Sepharose column as the adsorbent (Figure 1)

Summary

Introduction

Mammals are exposed to many factors that can affect their functions or even cause their demise Such factors can be xenobiotics, such as pesticides, environmental pollutants, and reactive oxygen species (ROS) [1,2]. These factors activate a detoxification mechanism, consisting of two phases (phase I and phase II) [3]. All cytosolic GSTs share a universal GST-fold [9]. They are dimeric enzymes, usually from identical chains, but heterodimers made of two different chains are found [10]. Two domains are recognized in each monomer: the conserved N-terminal

Methods

Results

Conclusion